I encountered this problem on a much earlier upgrade. The problem was due to a corrupted distribution specification for the task. Go into the task def for one of these tasks. Check the Distribute setting and make sure it is set to the correct folder and server. Even if it is, set it again and press the Apply button.
In my case, the tasks were found to have a folder setting called "Distrib" where they should have been using the Root. I used the QVPR analysis tool to find all tasks using folder Distrib and corrected them using QMC.
2. Don't create a server task for it, just reload it from your desktop.
3. It may be easiest if you take a copy of the QVPR folder from the server c:\ProgramData\ManagementService\QVPR to your desktop. An easy way to do that is copy over one of the .zip files from the QVPR\Backups folder and unzip to your machine.
Let me know if this helps.
As to the question of how the dist got corrupted, yes, mine happened during an upgrade. I never pursued the problem, just fixed it. I've done many upgrades and that is the only time I've experienced that problem. It was in a clustered QDS environment. Do you have more than one QDS?